| 摘要 |
<p>PURPOSE: To provide a binary system developer which does not contain any of a charge control agent, which does not scatter toner which is sufficient in chargeability and transfer efficiency, with which the toner has a high pulverability and which is excellent in fixing ability of a transferred image, fluidity and durability. CONSTITUTION: A binary system developer is composed of carrier and toner containing toner particles which in turn contain fixing resin and magnetic powder. The fixing resin is composed of a monomeric material and a polymeric material which respectively have an anionic polar component. The content ratio of the anionic polar group in the monomeric material is less than that of the polymeric material, and the SP value of the monomeric polymer is less than that of the polymeric material. Each of the carrier particles is composed of a core particle, and a cover layer with which the core particle is covered. recesses in the core particle, and covers 0.1 to 60% of the surface area, the core particle being made of a predetermined magnetic material, and the cover layer containing methyl silicone resin and methylated melamine resin having a predetermined molecular weights, or methyl silicone resin containing more than 70% of T-unit.</p> |
